US English Style Guide

Spelling and Expression Guide

American English has a lot of dialects and variations depending on geography, ranging from Pacific Northwest to Inland Northern to Southern, but for most purposes, “General American” will suit. These are just a few of the main rules to follow when trying to write or edit an English text for American English.

Common spelling styles

Words like “favorite,” “color,” “honor,” and “labor” are spelled without the “u” (the –or suffix replacing the British –our)

Words like “center” and “theater” are spelled –er, not the British –re

For past tense verbs, use the –ed ending (e.g., learned instead of learnt)

When using the –ize/–yze suffix (or its derivations), it is with a “z”, not an “s” (e.g., strategize, realize, collectivized, standardizing)

Verbs ending in –el do not double the “l”: “traveling” (not “travelling”) or “canceled” (not “cancelled”)

Use –e/–o/–eu (not –ae/–oe/–oeu) for words like archeology, estrogen, or medieval

Use “defense” and “license” (the –ense suffix replacing the British –ence)

Use “catalog” (the –og suffix replacing the British –ogue)

Use “program” (the –gram suffix replacing the British –gramme)

Use “check” (the –k or –ck suffix replacing the British –que)

Use “judgment” or “argument” (the –dg or -gu replacing the British –dge or –gue)

Punctuation

American English uses double quotes (“x”), and puts the punctuation inside the final double quote: “x.”

Single quotes (‘x’) are used when there is a quote within a quote: “He said, ‘Okay.’”

American English is quite intolerant of comma splices, so be sure to avoid this sentence structure

Units of measurement

Temperature is in Fahrenheit degrees

Measurement units are in miles, feet, yards, and inches

Dates are given in Month/Day/Year style (12/31/2016 is December 31, 2016) and Americans tend to use slashes or dashes between the numbers, not periods

Americans use a colon in expressions of time, not a period: 10:30 am (not 10.30 am)